So I hit somewhat of a snag while looking at the rear diffuser. The entire structure was slanted towards the rear. Newbie mistake, as I was mostly working at an angle, the car being on plastic ramps. I figured a way to shim the whole structure without much hassle though. Still has a slight slant, but it is good enough ..as they say. Lesson learned...
I added a smaller box in order to reduce the amount of 2-part foam needed. I also fixed the tow bar rattle/play with a u-clamp.
Started visualizing the curves and taper.
Cheers.